Silent Hill Experiment mod is my pick for this purpose. Then there's a heap of gloom mods, none of which caught my attention to any impressive extent. <rant> And if you're into that kind of thing: every mod hub is flooded with cancerous onslaught of shader hacks, like ENB, SweetFX, ReShade and so forth. This game has surprisingly few of those listed on Nexus but the hacks themselves are very generic, they support any game and their presets can be easily interchanged. Some "modders" even go as far as to chain together 3 or so of those hacks in order to completely ruin the palette of the game. You can take a preset made for Skyrim (popular hub — wide assortment) and apply it to SoD. </rant> As for "non-mod-inclined": you're in the wrong place and even then, there are only so much options the game provides. As @doomlorddan suggested, gamma setting is about it. It can enhance the effect of a mod but won't give you what you want on its own.